JPH08260454A - Constructing method of muddy-water solidified wall - Google Patents

Abstract

PURPOSE: To omit the waste and overlapping of facilities and materials while obtaining a homogeneous solidified wall by sucking muddy water previously filled into an excavated ditch and supplying the inside of the excavated ditch with muddy water while muddy water is mixed continuously with a hardener. CONSTITUTION: In a method, in which a muddy-water solidified wall is built by filling the inside of an excavated ditch 1 with the mixture 2a of muddy water and a hardener and curing the mixture 2a, an injection nozzle 14 projected and arranged into a suction chamber 12 for a jet pump 6 is supplied with the hardener through a high-pressure grouting pump 4. The other end side of a suction pipe 7, in which one end is connected to the suction chamber 12, is dipped in the surface layer side in the excavated ditch 1, and the other end side of a discharge pipe 8, in which one end is bonded at the discharging end of the jet pump 6, is dipped in a deep layer section in the excavated ditch 1. The inside of the suction chamber 12 is brought to negative pressure by ejection from the nozzle 14 of the hardener, and muddy water 2 previously filled into the excavated ditch 1 is evacuated into the suction chamber 12 through the suction pipe 7 by negative pressure, and the deep layer side of the excavated ditch 1 is fed with muddy water through the discharge pipe 8 while muddy water is mixed with the hardener.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mixing a hardening agent with muddy water used for excavating a trench and supplying the mixture into the trench to construct a solidified wall of muddy water.

[0002]

2. Description of the Related Art The muddy water solidification method is a method of constructing a solidified wall in the ground by adding a cement hardening agent to muddy water such as bentonite liquid used for excavation of an excavation groove to solidify the muddy water. In order to solidify this muddy water, there are conventionally various methods described below.

(1) A method of constructing a muddy water solidifying wall by carrying out an excavation work from the beginning using a self-hardening stable liquid containing a solidifying material added to muddy water and leaving it as it is after completion of the excavation. (2) Excavation is performed using normal mud, and after completion of excavation, a mixed solution of another mud and hardening material is supplied to the deep part of the excavation groove,
It is a method to replace solid muddy water to form a solidified wall. (3) A method of excavating using ordinary muddy water, adding a hardening material to this ordinary muddy water after completion of the excavation, mixing by air stirring or mechanical stirring, and then leaving it to construct a solidified wall.

[0004]

[Problems to be Solved by the Invention] However, (1)
In this method, since the specific gravity and viscosity of the stabilizing liquid itself are high, it is difficult to use it for normal excavation work, and after it is supplied into the excavation trench, solidification progresses with the passage of time. Not suitable for excavating time.

In the method (2), muddy water different from general muddy water-
Since a plant for mixing hardeners must be built, the equipment becomes large. Moreover, since the mixing plant is a batch type, the mud to be replaced cannot be used as it is as the raw mud for mixing. In the method (3), since the specific gravities of the muddy water and the hardener slurry are largely different, it is difficult to uniformly mix and stir, and it is difficult to design the strength of the solidified wall obtained for that purpose.

The present invention is intended to solve the above problems, and an object thereof is to suck muddy water which has already been filled in a ditch and continuously mix it with a hardening material to supply it into the ditch. In this way, a method for constructing a solidified muddy water wall is provided, which eliminates waste and duplication of equipment and materials and can obtain a uniform solidified wall.

[0007]

In order to achieve the above object, the present invention provides a method for constructing a muddy water solidifying wall by filling a mixture of muddy water and a hardening material in an excavation groove and hardening the mixture. While supplying to the ejection nozzle protrudingly arranged in the suction chamber of the jet pump via a high-pressure pump, the other end of the suction pipe whose one end is connected to the suction chamber is immersed in the surface layer portion in the excavation groove, And the other end of the discharge pipe, one end of which is connected to the discharge end of the jet pump, is immersed in the deep layer in the excavation groove, and the negative pressure is generated in the suction chamber by the ejection of the hardening material from the nozzle, The negative pressure is used to suck the muddy water previously filled in the excavation groove into the suction chamber through the suction pipe, and mix it with the hardening material to supply it to the deep side of the excavation groove through the discharge pipe. And

[0008]

According to the construction method described above, ordinary mud can be used for excavation of a ditch.

After the excavation, when the solidified wall is constructed, the hardened material is jetted into the suction chamber through the jet nozzle so that the suction chamber becomes a negative pressure, the mud filled in the excavation groove is sucked, and the inside of the jet pump is hardened together with the hardened material. The mixture is continuously mixed by flowing in a turbulent state, and the mixture can be sequentially filled through the discharge pipe from the deep portion of the trench.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a muddy water-hardening material mixing plant to which the method of the present invention is applied. The excavation groove 1 is excavated using muddy water 2 having a predetermined viscosity such as bentonite liquid. It is left behind and holds the hole wall. In this state, the mixing plant is assembled on the ground surface portion near the excavation groove 1 as shown in the figure, and after the assembly, the muddy water-hardening material mixture is supplied into the excavation groove 1.

The mixing plant is a cement milk plant 3 which is a hardener slurry, a high pressure grout pump 4 connected to the cement milk plant 3, and a jet whose rear end is connected to the discharge end of the high pressure grout pump 4 via a connection hose 5. Pump 6 and
One end is connected to the rear end side of the jet pump 6 in an orthogonal state, the other end side is immersed in the surface layer of the excavation groove 1, and the other end is connected to the discharge end of the jet pump 6, and the other end is connected to the excavation groove. 1 and a discharge pipe 8 immersed in a deep layer.

The cement milk plant 3 has a stirring tank 9
And a hopper 10 for supplying powder cement arranged on the stirring tank 9 and a pipe 11 for supplying tap water.
By rotating the stirring blade 9a provided in the above, water and cement powder are sequentially mixed to continuously produce slurry-like cement milk.

Although the jet pump 6 is illustrated in a relatively large size in the drawing, this is for convenience of description, and is actually small in size, and the suction chamber 12 at the rear end portion and the inside of the suction chamber 12 are illustrated. Nozzle 14 that is projected coaxially with the tip of the nozzle 14
A mixing pipe 15 that integrally extends to the tip of the suction chamber 12 facing the tip of the nozzle 14, and a suction pipe 16 that is orthogonal to the nozzle 14 and communicates with the inside of the suction chamber 12. The discharge end of the pipe 15 is connected to the discharge pipe 8, and the suction pipe 16 is connected to one end of the suction pipe 7.

The general principle of the jet pump 6 is that when the fluid is jetted from the nozzle 14, the inside of the suction chamber 12 becomes a negative pressure and the secondary fluid is drawn through the suction pipe 16. For this reason, the inside of the suction chamber 12 has the mixing pipe 15
The cross-section is sequentially narrowed down to the connection portion with and the minimum diameter portion is used as a jet injection jet portion 12a, and both fluids are jetted toward the mixing pipe 15 through the jet portion 12a.

The mixing tube 15 has a horn-shaped interior that gradually expands in diameter from the ejection portion 12a as a stirring portion 15a. When passing through the stirring portion 15a, a turbulent flow such as a swirling flow is generated as shown by an arrow. The cement milk and the muddy water 2 are uniformly mixed and discharged to the outside by the stirring effect of the turbulent flow.

Flowmeters 18 and 19 are connected to the connecting hose 5 and the suction pipe 7, respectively, and a flow rate adjusting valve 20 is connected to the connecting portion between the suction pipe 7 and the suction pipe 16. By adjusting the drive speed of the high pressure grout pump 4 and the opening of the adjusting valve 20 based on the numerical values indicated by the flowmeters 18 and 19, the optimum mixing ratio of the muddy water 2 and the cement milk can be adjusted.

Therefore, the cement milk continuously produced in the cement milk plant 3 by driving the grout pump 4 is injected into the suction chamber 12 by the nozzle 14,
As a result of the negative pressure, the muddy water 2 near the surface layer of the excavation groove 1 is sucked up through the suction pipe 7, and is uniformly mixed with the cement milk from the suction chamber 12 through the spouting portion 12a in the mixing portion within the mixing pipe 15, and this muddy water is mixed. -Cement mixture 2a
Flows from the tip of the mixing pipe 15 through the discharge pipe 8 to the groove bottom of the excavation groove 1 and is discharged.

At the stage where the mixture 2a is discharged from the mixing pipe 15 into the discharge pipe 8, the mixture 2a loses its velocity energy, and is discharged to the bottom of the groove only by the flow caused by the drop and is replaced with the muddy water 2 while being sequentially accumulated.

On the other hand, the muddy water is sequentially consumed from the surface layer 2, and the muddy water-cement mixture 2 is sequentially consumed according to the difference in specific gravity.
By being pushed up by a, the mixture is sucked by the jet pump 6 until just before the mixture is completely filled in the excavation groove 1, and continuous construction can be performed.

After the construction, the mixture 2a is solidified with the lapse of time and a mud solidified wall is constructed.

In the above embodiment, cement milk in which cement is dispersed and mixed in water is jet-injected to mix with muddy water. However, for example, cement alone or a hardening material can be injected as powder particles. Since it is possible to create a vacuum, it is possible to inject cement alone. In this case, the hardener slurry manufacturing plant can be omitted, the facility can be simplified, the water content ratio of the muddy water-hardener mixture can be reduced, and an early and strong muddy water solidifying wall can be constructed.

[0022]

As described above in detail with reference to the embodiments, the method for constructing a muddy water solidifying wall according to the present invention enables uniform mixing and continuous construction as compared with any conventional method. The advantage is that it has a large construction capacity and can obtain a homogeneous mud solidification wall.

Further, since the jet pump itself used in the construction plant is small, there is an advantage that the equipment itself for construction can be downsized.

[Brief description of drawings]

FIG. 1 is a construction explanatory view showing a muddy water-hardening material mixing plant to which the method of the present invention is applied.

[Explanation of symbols]

 1 excavation ditch 2 muddy water 2a muddy water-cement mixture 3 cement milk plant 4 high pressure grout pump 6 jet pump 7 suction pipe 8 discharge pipe 12 suction chamber 14 injection nozzle 15 mixing pipe 15a mixing part

Claims (1)

[Claims] 1. A method for constructing a solidified wall of muddy water by filling a mixture of muddy water and a hardening material in an excavation groove and hardening the mixture, wherein the hardening material is arranged to project into a suction chamber of a jet pump via a high pressure pump. A discharge pipe whose one end is connected to the discharge end of the jet pump while the other end side of the suction pipe whose one end is connected to the suction chamber is immersed in the surface layer portion inside the excavation groove. The other end side of which is dipped in a deep layer in the excavation groove, and a negative pressure is generated in the suction chamber by the ejection of the hardening material from the nozzle, and the negative pressure causes muddy water to be filled in the excavation groove in advance. Is suctioned into the suction chamber through the suction pipe, is mixed with the hardening material, and is supplied to the deep layer side of the excavation groove through the discharge pipe.